What is the fourth step in the firing sequence of a firearm?

The fourth step in the firing sequence of a firearm involves the high pressure created by gas. Once the trigger is squeezed, it releases the firing pin, which strikes the primer. This action causes the primer to explode and ignite the powder inside the cartridge. As the powder ignites, it generates a rapid expansion of gas, resulting in high pressure inside the chamber. This high-pressure buildup forces the bullet down the barrel and ultimately propels it toward the target.

In the context of the firing sequence, creating high pressure from the ignited powder is crucial because it directly leads to the bullet being expelled from the firearm. If this step doesn’t occur correctly, the bullet would not achieve the necessary velocity to exit the barrel effectively. Prior steps, such as squeezing the trigger and the primer's reaction, set the stage for this significant moment in the firing sequence. Thus, recognizing the importance of gas pressure in the function of a firearm helps in understanding the mechanics of how bullets are fired.